Synthesis of N-(2H-[1,2,4]Thiadiazolo[3′,2′:2,3] Thiazolo-[5,4-b]pyridin-2-ylidene)aroylamines

Abstract

The reaction of 2-aminothiazolo [5,4-b] pyridines (1) with aroyl isothiocyanates in acetone gave N-aroyl-N′-(thiazolo-[5,4-b] pyridin-2-yl)thioureas (2). Cyclisation of 2 in the presence of PCl₅ in POCl₃, as well as by oxidising agents like Br₂ in CHCl₃, Br₂ in AcOH and lead tetraacetate yielded N-(2H-[1,2,4] thiadiazolo [3′,2′:2,3] thiazolo [5,4-b] -pyridin-2-ylidene)aroylamines (4).